1. The Field of the Invention
The present invention is related to an apparatus for adjusting the height of a basketball goal and, more particularly, to a constant force adjustment assembly for a basketball goal assembly having an extension arm adjustable between a plurality of positions to facilitate the adjustment of the basketball goal over a playing surface.
2. Technical Background
Basketball is an increasingly popular sport in the United States and abroad. There are many cities, counties and other associations that sponsor recreational and instruction leagues where people of all ages can participate in the sport of basketball. Today there are organized leagues for children as young as five and six years old. Accordingly, is not surprising that more and more people have a basketball goal assembly mounted on their own property.
The problem with many basketball goal assemblies of the prior art is that the goal is usually fixed at a certain height above the playing surface, with a standard height being about ten (10) feet. Children and younger teens, however, generally don""t have the strength or agility to shoot and make a basket at the typical height of ten feet. Moreover, children tend to develop improper shooting skills by attempting to throw a basketball toward a goal that is disposed too high. Oftentimes, children or younger teens get frustrated with the sport of basketball and may give up the sport altogether.
Many attempts have been made by those skilled in the art to design basketball goal assemblies which are adjustable to several different heights. Adjustable basketball goal assemblies allow persons of all ages and sizes to enjoy the sport of basketball because the basketball goal can be adjusted to various heights above the playing surface. Some prior art basketball goal assemblies employ a deformable linkage design which generally connects the backboard to a rigid mount such as a support pole. In operation, prior art deformable linkages may be selectively locked at various positions to secure the basketball goal at a predetermined height above the playing surface.
One disadvantage of prior art deformable linkage devices is that the adjustment assembly is typically positioned within or near the linkage which is generally well above the playing surface. Accordingly, whenever a user desires to adjust the height of the basketball goal, the use of a ladder, stool or the like is required to enable the user to reach the adjustment assembly and xe2x80x9cunlockxe2x80x9d the basketball goal. Having to use a ladder, stool or the like to adjust the height of the basketball goal creates an inherent danger to the user of the potential for falling.
Other prior art adjustable basketball goal assemblies were developed having an adjustment assembly that is only accessible with the use of a separate rod or pole, such as a broomstick handle. Often times, there is not such an adjustment device readily available. The user must therefore accommodate the inconvenience of having to find a suitable implement, or simply choose not to adjust the height of the basketball goal.
Another disadvantage of many prior art adjustable basketball goal assemblies is that the mechanism for adjusting the height of the basketball goal is separate and distinct from the mechanism used to secure the goal assembly at a particular height. Thus, both hands of a user are normally needed to simultaneously unlock the adjustment mechanism, adjust the basketball goal and then lock the adjustment assembly at a predetermined position.
Some prior art basketball goal assemblies are configured with the adjustment assembly positioned adjacent the basketball playing area. Such adjustment assemblies can interfere with users, thereby creating a potentially dangerous situation. For example, such adjustable basketball goal assemblies are usually subject to inadvertent adjustment if bumped by a user or hit with a basketball.
Yet another disadvantage of prior art basketball goal assemblies is that the adjustment assembly is in tension with the linkage device attached to the goal; thus the locking or adjustment assembly is susceptible to separation upon failure and, accordingly, the goal assembly may drop into the playing area and cause potential injuries to users. Another disadvantage of prior art basketball goal adjustment assemblies is that many of the securing and adjustment assemblies require numerous working components and a complex design configuration to be able to simultaneously adjust and secure the basketball goal assembly in a predetermined position above a playing surface. This increases the cost, the difficulty of manufacture and the time required for a user to assemble the basketball goal.
Moreover, many prior art adjustable goal systems require a user to apply considerable force to operate them. Some mechanism is needed to provide an upward force, or counterbalancing force, on the basketball goal to counteract its weight. Several known adjustable systems have a counterweight positioned to rise when the goal falls, and vice versa, to provide a neutral balance, thereby making adjustment easier. However, this approach requires either the use of long, protruding members to provide a longer moment arm for the counterweight, or heavy weights to compensate for a shorter moment arm. Either solution is undesirable. Long counterweight extensions impede goal placement and possibly game play. Heavy weights make the entire assembly expensive to ship and difficult to move.
Springs, when used in the place of a counterweight, are prone to a different problem. Since the force provided by a spring increases with the spring""s deflection, the counterbalancing force increases along the goal""s range of adjustment. As a result, the counterbalancing force will be inadequate when the spring is nearly undeflected, i.e., when the goal is near the top of its range of adjustment, so that a user must bear a portion of the goal""s weight to adjust it. Similarly, when the goal is in a lower position, the counterbalancing force is too great, so that a user must fight the counterbalance to avoid adjusting the goal height more than desired. The unpredictability of such a mechanism is frustrating for users, who may have to make several adjustments to obtain a desired goal height.
Furthermore, many known adjustment assemblies are difficult to fine-tune because they are either locked in place, or unlocked for adjustment. Once unlocked, the goal adjustment assembly moves freely, so that it is difficult to make slight adjustments, especially if the counterbalancing force is too large, too small, or not present. Such free motion also creates a danger of injury from rapid adjustment. For example, a person standing underneath the goal may be injured if another person unlocks the adjustment mechanism, thereby allowing the backboard to fall rapidly.
Another disadvantage of many known adjustment assemblies is that they obstruct the space behind the backboard with springs, levers, and the like. As a result, an overshot ball may become lodged behind the backboard by the adjustment mechanism, or possibly trip or damage the adjustment mechanism. If the backboard is transparent, visible componentry of the adjustment assembly may distract players, especially if it shows through the square typically painted on backboards to help players aim at the basket.
From the foregoing, it will be appreciated that it would be an advancement in the art to provide an adjustable basketball goal assembly that can be adjusted without the use of a ladder or a pole. It would be a further advancement to provide such an adjustable basketball goal assembly that could be quickly and easily adjusted using a single hand of a user. It would be yet another advancement to provide an adjustable basketball goal assembly that does not interfere with game play and that would not endanger users if the adjustment or locking mechanism failed. Moreover, it would be another advancement in the art to provide an adjustable basketball goal assembly that is simple in design and cost effective relative to manufacture.
Furthermore, it would be an advancement in the art to provide an adjustable basketball goal system that is adjustable across a large range of goal heights with a substantially constant input force from a user. It would be a further advancement in the art to provide an adjustable basketball goal system with dampened motion, such that adjustment takes place in a measured, safe fashion. Yet further, it would be an advancement in the art to provide an adjustable basketball goal system in which components of the adjustment assembly are substantially removed from the area behind the backboard, so that overshot basketballs will not strike the adjustment mechanism, and players will not be distracted by additional parts behind a transparent backboard.
Such an adjustable basketball goal assembly is disclosed and claimed herein.
The present invention is directed to a novel adjustable basketball goal assembly having a constant force adjustment assembly that facilitates adjusting the height of a basketball goal above a playing surface. The basketball goal assembly of the present invention includes a support pole that extends in a substantially upward direction. The support pole has a goal side and a back side formed opposite the goal side. A deformable goal support structure may be pivotally attached to the goal side of the support pole such that the goal support structure is suspended above the playing surface. The goal support structure includes an upper support arm and a lower support arm. In one presently preferred embodiment of the present invention, one of the support arms has a tail section that extends substantially outward from the back side of the support pole.
A basketball goal is preferably attached to the goal support structure adjacent the goal side of the support pole. In one presently preferred embodiment, the goal comprises a rim, a backboard and a net. The goal support structure is preferably configured such that as the goal support structure deforms, the height of the basketball goal above the playing surface is correspondingly adjusted, wherein each variation in height of the basketball goal corresponds to a different deformation of the goal support structure. In operation, the goal support structure allows the rim of the basketball goal to be adjusted to several different heights while retaining the rim in a substantially horizontal disposition in relation to the playing surface.
In one presently preferred embodiment, a handle member is pivotally mounted at the back side of the support pole such that a user can adjust the handle member without needing a ladder, stool, pole or the like. An extension arm is preferably positioned between the parallelogrammic deformable goal support structure and the handle substantially along the back side of the support pole. A first end of the extension arm is pivotally attached to a cam fixture mounted on the tail section of the lower support arm and a second end of the extension arm is pivotally attached to the handle member. The handle member may include a distal end pivotally attached to the support pole and an intermediate portion pivotally attached contiguous a second end of the extension arm. In this configuration, an adjustment of the handle member moves the extension arm and deforms the parallelogrammic structure to thereby adjust the height of the basketball goal in relation to the playing surface. Thus, the height of the basketball goal can be adjusted without the use of a ladder or other adjustment implement.
In preferred design, a first resilient member, in the form of a gas spring, also pivotally engages the intermediate portion of the handle member and the support pole. The gas spring includes a first adjustment member telescopically engaged within a second adjustment member. One or more internal compressible fluids, such as a gas and an oil, operate to urge the first adjustment member out from the second adjustment member, thereby pressing the handle downward to oppose the weight of the basketball goal.
The gas spring has an internal valve structure operable by means of a rod extending through the first adjustment member. The rod actuates the internal valving to lock the gas spring against adjustment when the rod is drawn outward from the first adjustment member, and to permit adjustment when the rod is pressed into the first adjustment member. The rod is pivotally attached to a trigger, which is, in turn, pivotally attached to the handle member. The trigger acts as a lever, such that a user squeezing the trigger against the handle pushes the rod into the first adjustment member, thereby permitting adjustment of the gas spring. Once adjustment of the basketball goal assembly is completed, a user releases the trigger and the handle, and the rod is drawn from the first adjustment member to once again lock the gas spring. Hence, and the entire basketball goal assembly is locked in that configuration until the user once again grips the handle and squeezes the trigger.
When released, the gas spring, like a coil spring, provides a force proportional to its deflection. Thus, when the basketball goal is near its lowest point, the gas spring is greatly compressed and provides a large restorative force. When the basketball goal is near its highest point, the gas spring is only slightly compressed, so the restorative force is less. This changing force is compensated for by the cam fixture mounted on the tail section of the lower support arm.
The cam fixture provides an offset for the force of the gas spring, which acts on the goal support structure through the extension arm. The attachment point of the extension arm on the cam fixture is effectively drawn inward, toward the support pole, as the goal moves downward. This lessens the moment arm of the gas spring""s force on the lower support arm. The smaller moment arm compensates for the larger force of the gas spring when it is greatly compressed, as when the goal is lowered. Consequently, the moment exerted by the gas spring on the goal support structure, and therefore the upward force provided to counterbalance the weight of the basketball goal, remains substantially constant through the basketball goal""s entire range of adjustment.
The gas spring also tends to resist rapid adjustment. The internal fluids of the gas spring create an additional force that is opposed to and proportional to the velocity of adjustment in either direction. This may be called a dampening force because it tends to dampen rapid motion. Thus, the basketball goal assembly will only be adjustable at a relatively safe rate of speed, or rate of adjustment, even if a user is pushing or pulling the handle with considerable force.
In one presently preferred embodiment, a second resilient member is also provided. The second resilient member may include a second adjustment member telescopically engaged within a first adjustment member. However, a coil spring inside the first and second adjustment members may be used to provide the restorative force for the second resilient member. The second resilient member may be pivotally attached to the support pole and to the cam fixture, so that it functions similar to the first resilient member. More specifically, as the basketball goal is lowered, the spring stretches to a greater deflection, thereby providing a larger restorative force. The cam offset decreases the moment arm of this force against the goal support structure as the basketball goal is lowered, thereby providing a constant counterbalancing force against the basketball goal, substantially independent of the goal""s height above the playing surface.
The basketball goal assembly may also include a support base configured having an internal cavity sufficient for receiving and retaining a ballast material. The support base is configured such that when filled with a ballast material, the base stabilizes the adjustable basketball goal assembly and supports the support pole, disposed in a receiving aperture formed in the support base, in a substantially upright position.
Thus, it is an advantage of the present invention to provide an adjustable basketball goal assembly with an adjustment assembly in compression with the extension arm and which does not interfere with the playing area. It is another advantage of the present invention to be able to adjust the height of the basketball goal without the aid of a ladder or pole. It is a further advantage of the present invention to be able to easily adjust the height of the basketball goal using only a single hand of a user.
It is another advantage of the present invention to be able to adjust the height of the basketball goal by applying a constant external force, independent of the configuration of the basketball goal assembly. It is yet another advantage of the present invention to be able to safely and accurately adjust the height of the basketball goal through a dampening force provided by the adjustment mechanism. It is an additional advantage of the present invention to be able to adjust the height of the basketball goal without interference with game play from adjustment assembly components behind the backboard. Still further, it is an advantage of the present invention to provide an adjustable basketball goal assembly that is cost effective to manufacture and easy to assemble.